Material handling fan



March 31, 1953 D. A. BUSH 2,633,390

MATERIAL HANDLING FAN Filed Aug. 12, 1950 2 SPEETS-Sl-IEET l Snventor W45 A. 566/1* /4 i March 31, 1953 D. A. BUSH MATERIAL HANDLING FAN Filed, Aug. 12 1950 2 SHEETS-SHEET 2 r 0 t. n Z e m 3 f//////////.////// o n \\\\\\w\\\\ f 7 JAI Patented Mar. 31, 1953 MATERIAL HANDLING FAN Dale Allen Bush, Pine Bluff, Ark., assignor to Ben Pearson, Incorporated, Pine-Bluff, Ark., a corporation of Arkansas Application August 12, 1950, Serial No. 179,023

(Cl. PR02-illv s claims. 1

This invention relates to certain new and' useful improvements in fans for handling materials, particularly such material as cotton seed and also seed cotton as harvested -and picked from the cotton plant by mechanical cotton pickers, 'and is :adapted to serve as an exhaust fan for moving such material from the harvester and effecting delivery of same to a suitable receptacle.

The present invention is particularly related 'to such a fan or impeller in which material handling is satisfactorily and efciently accomplished, eliminating the undesired cracking of the cotton seed, such as has resulted heretofore from the centrifugal force exerted upon cotton handled by fans of pre-existing types.

The principal `object of this invention is to provide a fan for handling vmateria-ls in which the blades or vanes of the fan are so `arranged as to reduce the velocity of the cotton or other material las it passes along the surface of the said blades or vanes so as to eliminate cracking of seed in cotton and other damage to materials upon release of the material from contact with the fan blades.

A further object of the invention is to provide a material handling fan in which each of 'the blades or vanes consists of a segment of a spiral.

A further object `of the invention is to provide, in a fan, blades having tip sections in which the tip `sections are minor arcuately curved sections, the curvature of which is substantially concentric with the axis of rotation of the fan.

A further object of the invention is to provide a material handling fan blast wheel yconsisting of an imperforate backing plate, e. plurality of spiral-segment vanes fixed in edge relation to the plate perpendicularly thereto, in which each blade remote from the fan hub is provided with tip section, angularly intersecting the body of the blade and varcuately curved concentrically with the fan hub and lying substantially equidistant from the fan hub with the periphery of the backing plate.

A further object of the invention is to improve the design, construction and ei-ciency of impeller means for handling materials.

The means by which the foregoing and other objects of the present invention are `accomplished and themanner of their accomplishment will readily be seen from the following specification upon reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of an assembled fan unit in accord-ance with the present invention.

Fig: 2 is a side elevational view on an enlarged scale with part of the housing removed for purposes of illustration.

Fig. 3 is Ia front view, partly in elevation, further illustrating the yarrangement of the device.

Fig. 4 is a fragmentary front view on an enlarged scale illustrating'V the details of the blade tip section; and

Fig; 5 is a fragmentary sectional view taken as on the line V-v-V of Fig. 4.

Referring now to the drawings in which the various parts, are indicated by numerals, a housing is provided for the fan of the. present invention, which housing consists of a front plate Il, a rear plate I2 and a curved scroll :plate I3. Preferably a foot or pedestal I4 is provided to support the unit for use. lront and rear pla'tes II, I2, are flat plates formed with appropriately curving edges and are joined Ialong their edges by scroll plate I3, completing :a housing having a substantially -cylindrical body and provided with a tangential discharge I5, to which a discharge -conduit I 6 may be fixed to lead to la suitable receptacle, not shown.

Front plate II is provided with an aperture IT disposed slightly alcove and laterally oifset from the center of the cylindrical housing, to which aperture is attached' a forwardly projecting intake spout I'9, the spout' being preferably substantially frusto-conical in shape and being adapted to receive and have `fitted thereon a suitable piping 20 from a source of material such as a cotton harvester, not shown. Rear plate I2 is apertured in concentric alinement with intake opening I'I to receive la shaft 2|, a suitable bearing sleeve 23 being fixed to the exterior of rear plate I2 in yalinement with the aperture therein to provide journalling and support for shaft 2 I. Suitable drive means may be provided for the exterior shaft 2| in the form of apulley 25 mounted thereon which is coupled as by a belt 26 to a drive mechanism, not shown. The fan blast wheel of the present invention consists of a, substantially vertically disposed circular and imperforate impeller plate 2l, having a hollow hub 28 which is mounted upon and fixed in suitable fashion, as by a key to shaft 2|, for rotation with the shaft.

The fan wheel is completed by a plurality of blades or vanes 29 which are secured in edge relation to the forward face of impeller plate 2l and projecting perpendicularly from that face. The blades 29 are preferably identical and are spaced equidistant about the axis of rotation of the fan wheel,` the roots of each blade being abutted against and fixed to hub 28. Each blade 29 is preferably formed with its main body portion consisting of a segment of a geometrical spiral, the shape of each blade following a path as formed by a point rotated about the fan axis and constantly receding therefrom. The blades are so disposed upon the impeller plate that the blade root adjacent hub 28 is the leading portion of the blade in the direction of wheel rotation which is indicated by the arrow shown on Fig. 3, the path of the curve of the spiral segment body portion extending away from the hub in a counter-rotational direction. The spiral segment body portion of each blade preferably extends substantially to the periphery of impeller plate 2 and a tip section 3| is formed integrally with the spiral segment body portions and angularly joining the body portions along the line of junction, which line is substantially perpendicular to the impeller plate. Each of the tip sections 3l preferably comprises a segment of a cylinder, and is arcuately curved substantially concentrically with the axis of rotation of the fan and preferably having a radius substantially equal to the radius of impeller plate 21.

It will be seen that in the preferred embodiment of the fan the root and a substantial portion of each blade is embraced within the space bounded by the blade next preceding in the direction of fan rotation and that the terminal end of each tip section preferably lies substantially on that radius of the impeller plate extending through the root of the second following blade. Thus as indicated by the dotted line R on Fig. 3, the tip 3| of blade 25X lies substantially on the plate radius passing through the root of f lade 29Y.

In addition it is preferred that a minor end portion of each blade body and its integral tip section 3l should be cut off as at 33 along a diagonal line, providing a relief space at the outer and forward corner of each blade and its tip section, for the purpose of facilitating elimination of pos sible overload or packing of material in the housing. Preferably hub 28 extends rearwardly beyond the impeller plate so as to space the iinpeller plate a minor distance forwardly of rear plate I2 when the fan has been mounted in the housing. It is further preferred that the forward tip of sha-ft 2l should be tapered or formed conically in order to provide a divider for the stream of material flowing into the casing through intake spout I9.

In the use of the device after it has been assembled in the manner described, the fan wheel, as stated, is rotated in the direction of the arrow in Fig. 3, establishing a flow of air inwardly through intake spout i5, thence outwardly closely along the surface of the respective blades 2B dis-- charging peripherally about the fan and upwardly and outwardly through the tangential discharge l5. The movement of air thus created is adequate to withdraw cotton or other material through pipe 2D into spout i9 and the interior of the housing and to tangentially discharge the material for travel to a suitable receptacle through tangential discharge l and discharge pipe I5. It is found that when material such as cotton is delivered by the fan' it impinges against the forwardly projecting conical end of shaft 2l and is separated outwardly from the hub of the fan. It is engaged by the blades, the leading root portions of the blade face first effecting such engagement, and is found to move outwardly along the blades closely adhering to the surface of the blades. By Virtue of the counter-rota- 4 tional disposition of the curve of the blades the path of the cotton or other material being handled is found, in addition to being outward from the fan hub, to be slightly opposite to the direction of rotation, with the result that the velocity of the material is materially reduced until the cotton or other material has reached the tip sections 3l which abruptly drop olf in a counter-rotational direction and permit the cotton to leave the blade surface with minimum velocity being picked up and carried forward, thence to discharge by the current of air established by the fan. It is found that the centrifugal action exerted by fans heretofore in use, by which materials such as cotton has been thrown forcibly against the housing and seed cracking has been caused, is substantially completely eliminated, so that damage to cotton handled by the fan of the present invention is found to be reduced to a minimum. I y Due to the iiow of air about a properly curved surface the air stream and materials cling to the convex side of the blade reducing the velocity, then releasing the materials gently and at an angle to the scroll of fan and are then picked up by the air current and carried to the exhaust.

I claim:

l.. In a fan for handling seed cotton and the like, a housing, a fan blast wheel comprising a circular impeller plate rotatably mounted in said housing, means for rotating said plate in one drection, a central hub projecting from said plate, a plurality of identical curved blades, the roots of said blades being fixed to said hub in equally spaced relation, each said blade curving outwardly from said hub in a counterrotational direction along said plate, a like plurality of tip sections, each tip section being secured at one end in angular relation to the outer end of a blade with the other tip section end coinciding with the periphery of said plate, each said blade lying between two other said blades with said other end of the tip section of one of said other blades lying substantially on the radius of said plate which intersects the root of the second said other blade, whereby upon wheel rotation to handle and discharge seed cotton and the like substantially without impingement against said housing.

2. In a fan for handling seed cotton and the like, a housing, a fan blast wheel comprising an impeller plate rotatably mounted in said housing, 'means for rotating said plate in one direction, a central hub projecting from said plate, a plurality of identical blades each including a. spiral segment, the roots of said blades being fixed to said hub in equally spaced relation, each said blade spiralling outwardly from said hub in a counterrotational direction along said plate, a like plurality of tip sections, each tip section being secured at one end to the outer end of a blade angularly joining its spiral segment and projecting away from said segment in a counterrotational direction, and consisting of a segment of a cylinder centered on said hub, each s'aid blade lying between two other said blades with the other end of the tip section of one of said other blades lying on the radius of said cylinder which intersects the root of the second said other blade, whereby upon wheel rotation to handle and discharge seed cotton and the like substantially without impingement against said housing. 3. In a fan for handling seed cotton and the like, a housing, a fan blast wheel comprising an impeller plate rotatably mounted in said housing, means for rotating said plate in one directon, a central hub proj ecting'from said plate, a plurality of identical blades, the roots of said blades being fixed to said hub in equally spaced relation, each said blade extending outwardly from said hub along said plate,v a like plurality of tip sections, each tip section being secured at one end to the outer end of a blade, projecting in a counter-rotational direction away from said blade end, and consisting of a segment of a cylinder centered on said hub, each said blade lying between two other said1 blades with the other end of the tip section o'f`one of said other blades lying on the radius of said cylinder which intersects the root of the second said other blade, said blades and tip sections being truncated along one corner diagonally to said plate, whereby upon rotation of said plate to handle and discharge seed cotton and the like substantially Without impingeinent against said housing.

DALE ALLEN BUSH.

REFERENCES CITED The following references are of record ln the v le of this patent:

UNITED STATES PATENTS 

